综述了近年来木本植物适应酸性土壤的耐铝机理研究进展,重点以酸性土壤先锋植物胡枝子化espedezabicolor)和铝累积植物油茶(Camelliaoleifera)为例,总结了木本植物根系有机酸的分泌、铝吸收和运输机制及铝与氮磷胁迫的协同适应等。木本植物有铝累积和铝排斥植物之分;铝排斥植物胡枝子耐铝的重要机制是其根系同时分泌柠檬酸和苹果酸;铝累积植物油茶高效累积铝的原因在于其不仅可以高效吸收土壤和土壤溶液中广泛存在的铝(Al3+和Al—F),而且可以通过木质部运输和特定季节韧皮部运输的配合实现铝的高效分配和传输;铵态氮相对于硝态氮可缓解胡枝子的铝毒害;磷对不同胡枝子耐铝作用的影响明显不同。木本植物适应酸性土壤机理的深入研究将会有助于完善植物的耐铝机理及铝运输理论,并为酸性土壤中矿质养分管理提供理论基础。
The recent progresses on mechanisms of woody plants adaptation to acid soils were reviewed. This summary focused on organic acids secretion from woody plants roots under aluminum (Al) stress, mechanisms of Al uptake and transport, coadaptation mechanisms of woody plants to Al stress and different nitrogen or phosphorus stress, taking lespedeza (Lespedeza bicolor), a pioneer plant well adapted to acid infertile soils, and oil tea (Camellia oleifera), an Al hyperaccumulator, as examples. Woody plants could also be divided into Al accumulators and Al excluders according to Al accumulation in leaves, similar to herbs; The exudation of malate and citrate is one of the important Al-resistance mechanisms in L. bicolor; Oil tea could accumulate Al efficiently due to the efficient influx oral3+ and AI-F, widespread across acid soils, into the roots and its efficient distribution and transport of Al by the coordination between xylem transport and phloem transport in specific seasons; Ammonium alleviated the toxicity of Al in L. bicolor in solution culture compared withnitrate; Phosphorus enhanced Al resistance in the Al-resistant L. bicolor species but not in the Al-sensitive L. cuneata. Further investigation on mechanisms of woody plants adaptation to acid soils will contribute to the complement and improvement of the theories on Al tolerance and transport and to provide theoretic foundation for mineral nutrients management in acid soils.